The present application relates generally to an improved data processing apparatus and method and more specifically to mechanisms for unobtrusive failover in clustered network-attached storage.
A clustered file system is a file system that is shared by being simultaneously mounted on multiple servers. Clustered file systems can provide features like location-independent addressing and redundancy which improve reliability or reduce the complexity of the other parts of the cluster. Parallel file systems are a type of clustered file system that spread data across multiple storage nodes, usually for redundancy or performance.
Network-attached storage (NAS) provides both storage and a file system, like a shared disk file system on top of a storage area network (SAN). NAS is file-level computer data storage connected to a computer network providing data access to a heterogeneous group of clients. NAS not only operates as a file server, but is specialized for this task either by its hardware, software, or configuration of those elements. NAS is often manufactured as a computer appliance, a specialized computer built from the ground up for storing and serving files, rather than simply a general purpose computer being used for the role.
NAS systems are networked appliances which contain one or more hard drives, often arranged into logical, redundant storage containers or redundant array of independent disks (RAID). Network-attached storage removes the responsibility of file serving from other servers on the network. They typically provide access to files using network file sharing protocols such as network file system (NFS) or server message block/common Internet file system (SMB/CIFS).